The study looked at how the thickness of aluminum plates affects their resistance to fatigue. Thinner plates showed better fatigue properties. This is because thinner plates have smaller grain sizes, more grain boundaries, and substructures, which make them more resistant to fatigue crack growth. Thicker plates had larger grain sizes and fewer boundaries, making them more prone to fatigue. The researchers used various techniques like scanning electron microscopy and X-ray diffraction to analyze the plates. In conclusion, thinner aluminum plates are better at resisting fatigue compared to thicker ones.